


A/B/O primer for upcoming (Stucky) fics

by bubblewrapstargirl



Category: Captain America (Movies), Daredevil (TV), Marvel 616, Marvel Cinematic Universe, X-Men (Movies)
Genre: Alpha Bucky Barnes, Alpha/Beta/Omega Dynamics, Beta Steve Rogers, But Bucky/Steve is going to be the pairing in the actual fic which goes with this, Discussion of hypothetical relationships between many characters, F/F, F/M, Gen, M/M, Multi, Other
Language: English
Status: Completed
Published: 2015-07-26
Updated: 2015-07-26
Packaged: 2018-04-11 08:19:23
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,990
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4428158
Author URL: https://archiveofourown.org/users/bubblewrapstargirl/pseuds/bubblewrapstargirl
Summary: <blockquote class="userstuff">
              <p>This is not a fic, it is a general reference for my upcoming A/B/O fics set in the MCU (not relevant for my Walking Dead ABO fic), and may be used for other fandoms in the future. Just my own take on this universe and the biology involved, trying to explain my reasoning behind how spontaneously!genderswapping!betas work.</p>
            </blockquote>





	A/B/O primer for upcoming (Stucky) fics

This is a setting where all combinations of the genders (A/B/O) and the sexes (male/female) are possible.

(This is unusual for me as I generally write A/O as something that only affects males - they are all either alpha or omega, and all the women are betas, but sometimes I write it as females who are all either beta or omega).

I have never written female alphas before, and I wanted to address why not. I think we all come across tropes that make us think 'what?' and immediately back away from the story, and I think I found female alphas so off-putting because they never seemed like the actual characters they were supposed to be. The ones I came across were more like caricatures, cardboard cut-out Mary Sues that were aggressive and caused drama, written in merely to subvert female gender roles rather than have a storyline which furthered the plot. And if there's one thing I cannot abide, it's useless characters. 

So I had to think, what kind of female alpha would I write, if I had to write one?  And that got the ball rolling on other questions I'd considered before - like, what is the point of male and female betas? Some fics I read gave them a distinctive categorisation, but all too often they were a subset of humanity relegated into the background for being too dull. So how do you make betas interesting?

And this is basically what I came up with: betas that shift gender according to the gender of their sex partner.

In this verse are three 'genders':

alpha (males have knots)  
beta  
omega

and three 'sexes':

male   
female  
hermaphrodite*

*(using this term purely because 'intersex' doesn't seem to fit with characters that constantly switch gender, and this is the term most often used in A/B/O fics. Please bear in mind this is not me describing real people who are actually intersex)

alphas can be male or female  
omegas can be male or female  
all betas are hermaphrodites

HOWEVER at any given time, only one of a beta's sexes is active (fertile) and the other is dormant, and they are born with one active 'body type' (ie, their outer appearance, what we would use to identify a gender, such as the breasts and hips of a women, or the broad shoulders and flat chest of a man).

For example, a beta Steve Rogers, as a male in the MCU, would be described as an active male beta at birth. Using this method to write about betas, basically every character could be written as a beta and it would make sense, as you aren't describing a particular body type or gender/sex. Just a person.

This is where it gets more complicated:

Betas have 'reactionary DNA'. So depending on who they have sex with, they are either fertile or capable of impregnating another, and this is why **their active status at birth is important**. Regardless of whether they 'shift' from male to female, or remain their birth sex, their birth sex will determine how fertile they are with their chosen partner.

Keeping with the Steve example, because Steve was an active male at birth, his default is to produce fertile sperm. Although he has both male and female genitalia, the female is dormant - as a teenager he would not menstruate and could not, therefore, be impregnated, but he could impregnate another character. On the flip side, if you take a female MCU character, such as Pepper Potts, and designate her a beta, she would have been born an active female.

I should say at this point that females of A/O gender cannot impregnate anyone. Only female betas have this capability (as they have both male and female genitalia), but it is extremely rare, and only possible if they switch from being an active female to an active male.

If you are following so far, lets have a short recap:

Betas - both types of sex organs, but the one that is usable is the one which fits their body type (if they have breasts or not, basically). This is where that 'reactionary DNA' comes into play. Betas react to whoever they are having sex with/sexually aroused by/in close proximity to.

So an active female beta, from birth, would not be affected by being surrounded by males. However, if she was surrounded by fertile females, her body would 'shift', altering her muscle mass slightly, reducing the size of her breasts and activating her male DNA, so her sperm would become viable and she would no longer menstruate. She would then be termed an active male beta (even though she would still appear to look how we would term a woman). 

The same principle applies to male betas, active from birth. There is no limit to the amount of times a beta can shift.

Back to Steve again: if he was having regular sex with Bucky, that would activate his female DNA, and the process would be the reverse as the one I described above, and he would begin to menstruate. Unfortunately, betas cannot control/stop this process, even if they wish to remain one activation or another. So Steve might not be comfortable activating his female DNA, but if he chooses to have sex with a male alpha (Bucky), his body will automatically shift, and he would be referred to as an active female beta. 

A/B/O universes are geared toward one key goal; procreation. So, bearing in mind what I said above, these are combinations that could produce offspring, and would therefore induce heats/ruts in one another:

Alpha male/omega female   --alpha impregnates omega (usually results in birth of alpha)  
Alpha male/omega male   --alpha impregnates omega (usually results in birth of alpha)

^ these two combinations are the only pairings which produce 'thoroughbred alphas': winners of the genetic lottery, the social elite, the most powerful alphas whose enhanced abilities (sense of smell, advanced healing etc) are the very best (ie characters like Erik Lehnsherr, James Howlett (Wolverine), Bucky Barnes, Thor, Hank McCoy) and the reason why societies push their alphas into relationships with omegas.

Other combinations that produce offspring:

Alpha male/beta 'female' active from birth or shifted   --alpha impregnates beta  
Alpha male/alpha female   --only results in the birth of betas

Beta 'male' active from birth/alpha female   --beta impregnates alpha  
Beta 'male' shifted/alpha female   --extremely unlikely to result in viable pregnancy  
  
Beta 'male' active from birth/beta 'female' active from birth  --only results in birth of betas  
Beta 'male' shifted/beta 'female' shifted   --they would shift back to their active sex from birth, and then become the couple as stated above

Beta 'male' active from birth /male or female omega   --beta impregnates omega  


Beta 'male' shifted/female omega   --extremely unlikely to result in viable pregnancy  
Beta 'male' shifted/male omega   --only results in the birth of omegas

Combinations that do not produce offspring:

Alpha male/Alpha male (there are no eggs to impregnate) this could be a pairing like Clint/Coulson

Alpha female/any female (there is no sperm, unless a female beta is involved - but having sex with a female the beta's shift would be activated, then she would be termed a shifted male beta, which is a combo above)

Beta 'female' active from birth or shifted/male or female omega (again, a beta having sex with an omega would automatically shift into an active male anyway, but they would not be able to procreate in the period of time pre-shift)

Omega/omega (omega males do not produce viable sperm, and therefore cannot impregnate anyone. Female omegas obviously do not have the right sex organs to impregnate anyone either).

These pairings which are non-viable (do not result in offspring) are what would be considered homosexual in this A/B/O verse.

What about triads you say?

The traditional A/B/O triad of nomadic times, old fashioned in Shakespeare's heyday and virtually unheard of now, would consist of one of each of these genders. The combinations are many splendoured.

You could have:

Alpha female/beta/omega female (maybe Natasha/Tony/Pepper could be written like this, if we wrote Pepper as an omega instead of a beta)

Alpha male/beta/omega male (this combo could be Bucky/Steve/Johnny Storm for example) 

The shift or lack thereof of the beta in question (which sex organs are active and which are dormant) entirely depends on the sexes of their sex partner(s), so in these ancient triad type relationships, the sex would be active male for Tony, in a relationship with two women, but active female for Steve in a relationship with two men. (a!Natasha/b!Maria/o!Pepper would therefore result in an active male Maria).

What about when the sexes of the alpha and omega are different I hear you cry?

Let's take a!Foggy/b!Matt/o!Karen then.

Matt would be an active female beta in this relationship, because alpha genes are dominant, and they are the dominant person in their relationships, as a characteristic of their gender. Doesn't dictate the kind of sex they will have, more the strength of their pheromones, which is what causes a beta to shift.

However, if Foggy were abroad for a few months working on a case, Matt would shift to a male active beta, due to Karen's pheromones. Betas are the ones with the 'reactionary DNA' remember - they mould themselves into the 'correct' partner for the situation at hand, according to Mother Nature, whose object is procreation.

Beta!Steve therefore has perfect DNA to undergo experimentation with genes/DNA, since it's already malleable. In this verse, only betas were eligible for Project Rebirth.

Instead of being considered less sexual beings in this verse, betas would experience heats in their female form, and ruts in their male form, and be considered highly sexed figures in myth and modern fiction. Essentially, betas have the ability to shift between being a male alpha (but only actual male alphas have a knot) and a female omega, the only real difference being the type of offspring they produce (active male betas will never be able to father a thoroughbred alpha, for example).

Some prejudice exists, in that some sectors of society regard betas as 'false alphas', or 'false omegas' if they shift. This is true of certain religions or time periods, where it is believed that the active sex organs you were born with are the ones your god(s) intended for you to use.

Therefore, this is an issue for Steve and Bucky, Catholics who grew up in the 30s. Many back then would have believed Steve should have been pursuing female omegas (which would prevent him from ever shifting into an active female beta), and that Bucky was doing him a disservice hanging around, causing Steve to shift, menstruate and experience heats.

Omegas have heats every three months, active female betas experience them every six months. Omegas are the most fertile of the three genders, with the ability to be impregnated one more time at any stage of a current pregnancy.

For example, if a!Foggy impregnated o!Karen, at any time during the nine month gestation he could impregnate her again, and both pregnancies would be viable. Impregnation usually happens during heats, but omegas are highly fertile all year round. Multiple births of 'true twins' or 'true triplets' (babies who were actually conceived during the same round of intercourse, rather than those conceived weeks or months apart) are rare outside of heat. Babies who shared a womb but were not conceived at the same time are called time-split or split twins.

\---

I hope you liked this little look into my A/B/O verse. Please feel free to ask questions. I know this is highly focused on betas, so there might be info I have overlooked regarding my alphas and omegas.


End file.
